Oil-less Turboshaft Engine with Integrated Free Turbine Shaft

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Solution Overview

Problem

The existing lubrication systems in helicopter turbine engines are restrictive, prone to leaks, heavy, expensive, and polluting, requiring frequent pilot intervention and certification for lubrication interruptions.

Innovation Solution

A turbomachine architecture that eliminates the need for an oil lubrication system by using non-lubricated bearings and integrating electric motors to reduce the size and complexity of the lubrication system, with the main gearbox handling speed reduction and axial force absorption, and a brushless generator providing electrical power.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional lubrication system is used in the turbine engine, then the bearings are properly lubricated, but the system becomes heavy, complex, and prone to leaks

Engineering Contradiction:
Improvebearing lubricationVSAvoidlubrication system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the lubrication system entirely from the turbine engine by using non-lubricated bearings. The bearings are designed to operate without oil, eliminating the pump, filtration assembly, pipes, reservoir, cooling system, and degassing system that would otherwise be required.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical lubrication system with a different bearing design that does not require lubrication. This substitution eliminates the need for oil circulation mechanisms and associated components, reducing overall system complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If a traditional lubrication system is used in the turbine engine, then the bearings are properly lubricated, but the system becomes heavy

Engineering Contradiction:
Improvebearing lubricationVSAvoidlubrication system
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent removes the lubrication system entirely from the turbine engine by using non-lubricated bearings. The bearings are designed to operate without oil, eliminating the pump, filtration assembly, pipes, reservoir, cooling system, and degassing system that would otherwise be required.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If a traditional lubrication system is used in the turbine engine, then the bearings are properly lubricated, but the system is polluting and expensive

Engineering Contradiction:
Improvebearing lubricationVSAvoidpollution
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent removes the lubrication system entirely from the turbine engine by using non-lubricated bearings. The bearings are designed to operate without oil, eliminating the pump, filtration assembly, pipes, reservoir, cooling system, and degassing system that would otherwise be required.

Inventive Principle:
Principle #2Taking out (Extraction)

4Speed

If the free turbine shaft extends inside the main gearbox, then speed reduction is achieved, but the turbine engine requires integration with the main gearbox structure

Engineering Contradiction:
Improvespeed reductionVSAvoidintegration structure
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The patent merges the turbine engine with the main gearbox by having the free turbine shaft extend inside and connect directly to the speed reduction device. This integration eliminates the need for a separate reducer and accessory box, combining multiple functions into a unified structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The main gearbox is designed to serve multiple functions: it houses the speed reduction device connected to the free turbine shaft, provides structural support, and eliminates the need for separate accessory boxes and reducers. This multi-functionality reduces overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution results in a lighter, less expensive, and less polluting turbine engine architecture with reduced maintenance needs, as it eliminates the requirement for oil lubrication, enhancing operational reliability and reducing environmental impact.

Implementation Method 1

a free turbine driven in rotation by the flow of gas generated by the gas generator

Methodology Applied
Scientific EffectKinetic energy conversion: Turbine

Implementation Method 2

the fresh air entering the turbine engine is compressed due to the rotation of the compressor

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 3

where it is mixed with fuel. The gases burnt due to the combustion are then evacuated at high speed

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP2582923B1Oil-less turboshaft engine configuration
Publication Date: 2020.01.01 SAFRAN HELICOPTER ENGINES
  • EP2582923B1 patent drawingFigure 1~4
  • EP2582923B1 patent drawingFigure 2
  • EP2582923B1 patent drawingFigure 3

AI summary

The invention relates to a turbine engine (100) for a helicopter (200), said helicopter comprising a main gearbox, a rotor (204), and a speed-reducing device (206) that is placed entirely within the main gearbox (202) of the helicopter while being connected to said rotor, the turbine engine including a casing (102), a gas generator (114) having a gas generator shaft (115), and a free turbine (124) to be rotated by the gas flow generated by the gas generator, said free turbine comprising a free turbine shaft (128). According to the turbine engine of the invention, when the casing of the turbine engine is attached to the body of the helicopter, the free turbine shaft axially extends inside the main gearbox of the helicopter so as to be directly connected to the speed-reducing device.